Impact-modified polyamide compositions

ABSTRACT

Described herein are polyamide compositions and processes for producing polyamide compositions, comprising: (i) a polyamide, (ii) an olefin-maleic anhydride copolymer (on its own or in a master batch form), and (iii) an impact modifier (or an elastomeric polymer with an optional compatibilizer), which exhibit enhanced ambient and low temperature impact strength complimented by excellent thermal, tensile and flexural properties.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage application under 35 U.S.C. §371(b) of International Application No. PCT/US2014/027451 filed Mar. 14,2014, and claims the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application No. 61/788,900, filed on Mar. 15, 2013.The entirety of the contents of each of which are herein incorporated byreference.

BACKGROUND

Polyamide (nylon) thermoplastic resins offer an excellent balance ofprocessability and performance properties and therefore are used widely.Of the many types of nylon available, the most common are Polyamide-6and Polyamide-6,6. However, some end-use applications for these resinsrequire improved impact performance at ambient or low temperatures. Forthese applications, polyamide is usually toughened by impact modifiersalso called “tougheners”. Polymer toughness, in the form of impactstrength or resistance, is a measure of the ability of a material orprocessed article to withstand the application of a sudden load without“failure”.

Illustrative polyamide impact modifiers that can be used for thispurpose are grafted-maleic anhydride elastomers or terpolymers where thelevel of maleic anhydride is usually less than 5% and typically in therange of 0.8 to 2%. Examples from the class of maleic-anhydride graftedelastomers are thermoplastic olefins (TPO) also called reactor TPOs,rubber copolymers produced in a reactor from ethylene and propylene(EPR), or rubber terpolymers of ethylene, propylene and diene-modifier(EPDM), plastomers of ethylene with an alpha-olefin, etc., all graftedwith maleic anhydride off-line and random terpolymers of ethylene,acrylic ester and maleic anhydride with typical maleic anhydridecontents in the range of 1-5%. In the case of EPDM, typically dienescurrently used in the manufacture of EPDM rubbers are dicyclopentadiene(DCPD), ethylidene norbornene (ENB), and vinyl norbornene (VNB) used ata 1-12% level. Other examples include maleic-anhydride grafted olefinicthermoplastic elastomers (TPE) produced from copolymers of monomers likebutadiene, isoprene, propylene, ethylene, butene and octene, whichbehave like elastomers in performance but process like thermoplastics.Styrenic type modifiers such as linear tri-block copolymer of styrene,ethylene and butylene with grafted maleic-anhydride groups are alsosometimes used. Another example of an impact modifier is a terpolymerlike an ethylene-acrylate ester-maleic anhydride terpolymer, where theacrylate ester is a methyl, propyl, butyl and other acrylate esters. Itis well known to one skilled in the art that these elastomeric materialswithout the compatibilizing functional maleic anhydride group are notable to provide impact strength improvement to the compound, because insuch a case the nylon and the elastomeric phase in the toughener havelimited or no interaction and stress cannot be transferred from therigid polyamide phase to the elastomeric phase which can withstand theimpact energy. The use of these maleic-grafted elastomers to impartimpact resistance to polyamides has been in commercial use for severaldecades and has been previously described in U.S. Pat. Nos. 4,174,358and 4,594,386. Other impact modifiers used are the acrylic core-shelltype such as the Paraloid® product line from The Dow Chemical Company.Grades that work well for polyamides are the polymers or copolymers withmaleic anhydride pendant groups or with isocyanate groups. Occasionallyionomers such as Surlyn are also used as impact modifiers in polyamidesbut only for end use applications where low temperature impact is notrequired. Compatibilizers (i.e. polymers or copolymers that, when addedto an immiscible polymer blend, modify the blend's interfacial characterand stabilizes its morphology) can be added with elastomeric materialsthat do not include compatibilizing functional groups.

Addition of a “good” toughener results in “no break” of the test sampleduring the notched Izod impact strength with typical values greater than800 J/m (15 ft-lb/in.) at room temperature when used at levels between15-25 weight %. The impact strength measured by the notched Izod methodor by Charpy impact method depends on testing temperature. Use of anylon modifier may provide high values of toughness at room temperature,yet only achieve a lower level of toughness below or at −30° C.Typically, the stiffness, thermal properties like softening point andheat deflection temperature (HDT) of a toughened polyamide decrease asmore toughener is added with significant decreases in properties, e.g.flex modulus and tensile strength. Also the more elastomeric or itslower the glass transition temperature (T_(g)) the underlying impactmodifier the better is its impact strength at low temperature. The sametrend in physical properties is observed when the polyamide beingtoughened is reinforced with reinforcements like glass fibers,wollastonite or talc mineral fillers and/or flame retardants to formpolyamide composites.

It is commonly accepted in the plastics compounding industry that whenthese impact modifiers are compounded into polyamides, there arenegative effects on other properties such as tensile strength, tensilemodulus, flexural modulus and strength as well as thermal propertiessuch as heat deflection temperature (HDT) and softening point. Howeverfrom an end user perspective, there remains a need for polyamidecompounds with material compositions which mitigate these negativeeffects. There is a need in the marketplace for compositions which yieldhigh values of impact performance of the polyamide compound withoutcausing significant decrease in its other mechanical properties (i.e.retaining or even improving the impact properties of parts produced fromsuch modified polyamide compounds and molded or extruded articlesproduced from those compositions).

SUMMARY

Described herein are polyamide compositions that comprise:

a. a polyamide,

b. an olefin-maleic anhydride copolymer (may be added directly or in theform of a master batch formulation), and

c. an impact modifier (or an elastomeric polymer with an optionalcompatibilizer).

Also described herein is compounding the polyamide composition at itsprocessing temperature in a compounding extruder to produce impactmodified polyamide with high values of impact strength at roomtemperature and low temperature. The polyamide compositions describedherein have surprisingly improved mechanical properties compared topolyamide compositions prepared using the impact modifier alone.

DETAILED DESCRIPTION

The terms “elastomeric material” and “elastomer” will be usedinterchangeably herein and generally refer to polymeric materials whichexhibit typical elastomeric properties (tensile elongation greater thanabout 200%, Izod impact strength showing no break, crystallinity belowabout 3%, and a glass transition temperature below 0° C.,). Illustrativepolymers for use as the elastomer include, but are not limited toethylene-acrylate ester copolymers (e.g. copolymers of ethylene andn-butyl acrylate, methyl acrylate, or ethyl acrylate, and the like)where the co-monomers content is greater than 18%, thermoplastic olefins(TPOs), and thermoplastic elastomers (TPEs). Examples of TPOs and TPEsinclude plastomers, flexomers, ethylene-propylene copolymer rubber(EPR), ethylene-propylene-diene terpolymer rubber (EPDM),styrene-butadiene rubber (SBR), hydrogenated styrene-butadienecopolymers called styrene-ethylene-butene-styrene block copolymers(SEBS), ethylene-octene copolymers, ethylene-hexene copolymers,ethylene-4 methyl pentene-1 copolymers, and ethylene-butene copolymerswith specific gravity below 0.900 g/ml, and the like. Selection ofgrades with lower molecular weight and higher melt index may result inminimizing high torque conditions during processing and/or provide awider process window.

The optional compatibilizer can be selected from olefinicsemi-crystalline thermoplastics like polyethylene and polypropylene witha grafted functional group selected from one of the following:anhydride, acid chloride, carboxylic acid, isocyanate, and otherreactive groups. Examples of such polymers are Polybond® 1001 and 3200from Addivant, Nucrel® and Fusabond® from DuPont, Amplify® and Primacor®from The Dow Chemical Co., Exxelor® from Exxon Mobil Chemicals, and thelike.

It is described herein that either an elastomer with a compatibilizercan be used or a traditional impact modifier can be used as the thirdcomponent (c).

Described herein is the surprising discovery that polyamide compositionswith high values of impact strength can be produced with improvements inother mechanical properties such as tensile strength, HDT and flexuralmodulus by adding an olefin-maleic anhydride copolymer to thecomposition. In contrast to the worsening of those other mechanicalproperties that is normally associated with addition of an impactmodifier alone.

The use of olefin-maleic anhydride copolymers, which are highly reactiveadditives, to form polymer formulations with polyamides having improvedtensile strength, impact strength and other mechanical properties havebeen previously described in PCT International Publication No. WO2012/024268A1 and in corresponding U.S. Patent Publication 2013/0150517.Described herein are polyamide compositions, and processes for preparingthem, where the combination of the polyamide, impact modifier and theolefin-maleic anhydride copolymers, surprisingly results in mitigationof the expected negative effect of including the impact modifier inpolyamide composition, thereby providing compositions with an overalldesirable combination of mechanical properties such as tensile strength,tensile modulus, tensile elongation, flexural modulus, flexuralstrength, heat distortion temperature (HDT), softening point, as well asimpact strength at room and low temperature.

In another embodiment, the olefin-maleic anhydride copolymer can bepre-mixed with a carrier resin to form a master batch which can be addedto the polyamide, as described in PCT International Publication No. WO2014/008330 A2.

Described herein are polymer formulations comprising polyamidescompounded with one or more elastomers or tougheners and olefin-maleicanhydride copolymers. It is appreciated that the compositions may beprepared by combining all of the components in a single step or bycombining the olefin-maleic anhydride copolymer in a master batchfollowed by combining the polyamide with the master batch. Somedesirable characteristics of the master batch approach include: improveduniformity of the incorporation of the olefin-maleic anhydride copolymeradditive in the final composition and reduction of the processing torqueof the final polymer composition during processing. Desirablecharacteristics of the carrier resin used to form the master batchinclude: the carrier resin does not react with the additives, theadditives do not phase separate from the carrier resin, the carrierresin does not phase separate with the polymer being formulated, thecarrier resin of the master batch remains thermally stable at theprocessing temperatures and under the processing conditions typicallyused for processing polyamides, and the overall composition should beuseful in improving impact and stiffness of the polyamide. In anotherembodiment, the polyamide composition is formed by compounding theolefin-maleic anhydride copolymer/elastomer master batch, which isprepared by combining the olefin-maleic anhydride copolymer withelastomers, with the polyamide or nylon and optionally another elastomerand/or a compatibilizer.

Illustrative embodiments described herein include use of processingmethods such as extrusion compounding using equipment known to oneskilled in the art. In the plastics industry, compounding is a processthat mixes one or more polymers with one or more additives to produceplastic compounds in one or more steps. The feeds may be pellets, powderand/or liquids, but the product is usually in pellet form, to be used inother plastic-forming processes such as extrusion and injection molding.

Other illustrative embodiments of the methods described herein includedirectly extruding the compounding mixture into a finished article suchas a filament, fiber, film, sheet, and molded part. It is to beunderstood that the compounding step may include a reaction between oneor more of the components of the mixture.

In any of the methods or compositions described herein, other additivesmay be used depending upon the end use application. Such additivesinclude one or more anti-oxidants, UV stabilizers, or UV absorbents,halogenated or non-halogenated flame retardant additives, reinforcementssuch a mineral or fibers, fabrics, roving filaments, tubes and yarns,made from glass, carbon, graphite, cellulose and other naturalmaterials; and/or aromatic high melting polymers (sometimes referred toas aramids) are included. Plasticizers, lubricants, rheology modifiers,friction modifiers, and other additives known to one skilled in the artmay also be optionally added. Illustrative additives include colorants,heat stabilizers, light stabilizers, polymerization regulators,plasticizers, lubricants, rheology modifiers, flame retardants,reinforcing agents, friction modifiers, anti-blocking agents,antioxidants, antistatic agents, pigments, dyes, fillers or mixturesthereof.

The olefin-maleic anhydride copolymer used in the compositions describedherein is not a grafted copolymer with one or two maleic anhydridegroups per molecular chain, but a true copolymer with multiple maleicanhydride groups on the main chain of the polymer. In one embodiment,the olefin-maleic anhydride copolymer is an alternating copolymer of theolefin and maleic anhydride. In any of the methods or compositionsdescribed herein the olefin can be selected from ethylene, propylene,isobutylene, 1-butene, 1-octene, butadiene, styrene, isoprene, styrene,1-hexene, 1-dodecene, 1-tetradecene and other alkenes. Other copolymerslike methyl and butyl acrylate can also be used with the maleicanhydride.

In any of the methods or compositions described herein, theolefin-maleic anhydride can be an ethylene maleic anhydride alternatingcopolymer (EMA) with a molar ratio of ethylene to maleic anhydride ofabout 1:1. In any of the methods or compositions described herein, theolefin-maleic anhydride can be an ethylene maleic anhydride alternatingcopolymer (EMA) with a molar ratio of ethylene to maleic anhydride ofabout 1:99 to about 99:1. In any of the methods or compositionsdescribed herein, the olefin-maleic anhydride copolymer can be anon-alternating copolymer or a random copolymer with a molar ratio ofethylene to maleic anhydride range of about 1:50 to about 50:1; about1:20 to about 20:1; about 1:10 to about 10:1; about 1:5 to about 5:1;and about 1:2 to about 2:1.

In any of the methods or compositions described herein, theolefin-maleic anhydride copolymer can have a weight average molecularweight of in the range of about 1000 to about 900,000; about 20,000 toabout 800,000; about 40,000 to about 600,000; about 50,000 to about500,000; or about 60,000 to about 400,000. In any of the methods orcompositions described herein, the 1:1 alternating olefin-maleicanhydride copolymer selected may be a 1:1 alternating copolymer ofethylene and maleic anhydride (1:1 EMA) with a molecular weight of about60,000 such as that sold under the trademark ZeMac® E-60 (VertellusSpecialties Inc., E60), or the 1:1 EMA selected may have a molecularweight of about 400,000 such as that sold under the trademark ZeMac®E-400 (Vertellus Specialties Inc., E400).

Olefin-maleic anhydride copolymers are typically powders with varyingmolecular weight that can react with polyamide during the extrusionprocess acting as chain-extenders.

In any of the processes or compositions described herein comprising anolefin-maleic anhydride copolymers master batch, the master batchcomprises one or more additives, a thermally stable high melt flowpolymer and a compatible carrier resin. Illustrative polymers for use ascarrier resins include, but are not limited to ethylene-ester copolymers(e.g. copolymers of ethylene and n-butyl acrylate, methyl acrylate, orethyl acrylate, and the like); polyamides, polyamides wherein amine endgroups are capped (e.g. with acetyl or other suitable groups), or theend groups are carboxylic acid groups and not amines;polysulfonylamides, where the end groups are not amines; polycarbonates,where the end groups are carboxylic acid groups and not alcohols; andpolyesters, where the end groups are carboxylic acid groups and notalcohols; or combinations thereof.

Other additives may also be used in the compositions based on the enduse application. Illustrative additives include, but are not limited to,anti-oxidants, nucleating agents, colorants, plasticizers, lubricants,rheology modifiers, friction modifiers, other processing aids, and heatstabilizers for polyamides. As shown in the illustrative examplesdescribed herein, an unexpected increase in the mechanical propertyenhancement in polyamides formulations formed by compounding a polyamidewith the olefin-maleic anhydride copolymer master batch and toughener isseen compared to compounding the olefin-maleic anhydride copolymer, thetoughener (elastomer), and the polyamide in a single step. Polyamidecompositions including olefin-maleic anhydride copolymers but withoutthe impact modifier are described in WO 2012/024268 A1 the disclosure ofwhich is herein incorporated by reference.

It is believed that the compositions described herein increase theimpact properties and tensile elongation properties withoutsubstantially reducing other mechanical properties such as flexuralmodulus and tensile strength of the polyamide by chain extension of thepolyamide. An illustrative application of the compositions describedherein is to upgrade recycled polyamide or nylon. In this context theterm “recycled” can include reprocessed, regrind, and reclaimedpolyamide as well as “off-spec” polyamide. The compositions describedherein can also be used to improve the properties of virgin polyamides.

Injection molding is one of the commonly applied processes for the finalconversion of the compositions described herein, it is to be noted thatthe compositions described herein are useful in other processes such asblow molding, roto-forming, fiber forming, film, profile and sheetextrusion and thermoforming.

Described herein are compositions, comprising a polyamide, anolefin-maleic anhydride copolymer, an elastomeric polymer and optionalstabilizers and other additives. Also described herein are compositions,comprising an ethylene-maleic anhydride copolymer and one or moreelastomers or tougheners with an optional stabilizers. The stabilizerpackage includes additives used individually or in combination.Illustrative stabilizers include, but are not limited to, one or morephenolic antioxidants such asN,N′-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)](like Irganox® 1098 and BNX1098), phosphites such astris(2,4-di-tert-butylphenyl)phosphite (like Irgaphos® 168 and Benefos®1680), cuprous iodide (CuI), and/or potassium iodide (KI). It isappreciated that the person skilled in the art of polymer compoundingcan choose an appropriate combination of additives or stabilizers forthe polyamide, processing conditions, and intended use of the polyamidecomposition. In one illustrative embodiment, the stabilizer may bepresent in about 0.01% to about 5.0% w/w of the overall polymerformulation, or about 0.1% to about 2.0% w/w; or about 0.25% to 1.0% w/win the final composition and in the range of about 1.0% to about 30% w/wor about 5.0 to about 15% w/w in the master batch.

Plasticizers, lubricants, colorants, rheology modifiers, frictionmodifiers, UV stabilizers, flame retardants, reinforcements, fillers andother additives known to one skilled in the art may be optionally addedto the polyamide composition described herein depending on theapplication requirements.

In one embodiment, the method of producing polymer compositions ofpolyamides by compounding the polyamide with an elastomeric polymer, andan olefin-maleic anhydride polymer as described herein results inincreases in the polyamide's molecular weight and/or favorablestructural changes resulting in substantially improved impact strengthand stretch performance (known as tensile elongation) in addition toimprovement in other properties such as tensile strength, flexuralmodulus, and heat deflection temperature.

In an illustrative embodiment of the method of producing a compoundedpolyamide described herein, the method optionally further comprises thestep of converting the composition using a method known to one skilledin the art such as injection molding of the compounded polyamide.Optionally, the polyamide may be combined with the master batch ofolefin-maleic anhydride copolymer directly during injection molding.

The compositions describe herein are usually formed into a pellet form,to be used later in other plastic-forming processes such as extrusion,thermoforming, blow molding, and/or injection molding. Use of twin-screwextruders or continuous mixers for preparation of compositions describedherein is preferred where the extruder is equipped with feeders equippedto handle low bulk density powder because they give better mixing atlower melt temperatures. Most of these have screws and barrels made upof segments for mixing, conveying, venting, and additive feeding. Whenthe carrier resin is more flexible it may be advantageous to use otherplastics compounding equipment such as single-screw extruders,oscillating screw extrusion, continuous mixers, Banbury mixers, andplanetary extruders for compounding as well. Processing parameters suchas the temperature of each segment or zone, feed rates, residence timeand screw design and speed can be modified by the person skilled in theart for each application.

Polyamides are typically condensation copolymers formed by reaction ofdicarboxylic acids with diamines or by ring opening of lactams. Variouspolyamides can be created by adjusting the number of carbons. Thenomenclature used herein designates the number of carbon atom in thediamine first and the number of carbons atoms in the diacid second.Therefore, Polyamide-6,6 has six carbons from the diamine, and sixcarbons from the diacid, and Polyamide-6,12 would have six carbons fromthe diamine and twelve carbons from the diacid. Polyamide-6 is ahomopolymer formed by a ring-opening polymerization (i.e. ring-openingpolymerization of caprolactam). The polyamide may also be nylon-9,nylon-12, nylon-11, nylon 4,6, nylon 6,10, or any of the polyamideslisted herein.

In one embodiment, the olefin-maleic anhydride copolymer (e.g. ZeMac) isincorporated during the process of producing the maleicanhydride-grafted impact modifier, which involves adding maleicanhydride monomer and a peroxide catalyst to the unmodified elastomer(for example, to a metallocene ethylene-octene copolymer commonly knownas a flexomer or plastomer). It is expected by one skilled in the artthat under the typical conditions used to form the maleicanhydride-grafted impact modifier, the olefin-maleic anhydride copolymeris not significantly incorporated covalently into the maleicanhydride-grafted impact modifier. The resulting composition is thencompounded with nylon to produce the impact modified compositions.

Several illustrative embodiments of the invention are described by thefollowing clauses:

-   -   A polyamide composition produced by a process comprising the        step of compounding a mixture comprising a polyamide; one or        more elastomers; and an olefin-maleic anhydride copolymer.    -   A polyamide composition produced by a process comprising the        step of compounding a mixture comprising,        -   (a) a polyamide,        -   (b) an olefin-maleic anhydride copolymer, and        -   (c) an impact modifier.    -   A polyamide composition produced by a process comprising the        steps of:        -   (a) preparing a master batch composition comprising an            elastomer impact modifier and an olefin-maleic anhydride            copolymer; and        -   (b) compounding a polyamide with the master batch            composition.    -   The polyamide composition of the preceding clause wherein the        impact modifier olefin-maleic anhydride copolymer master batch        composition is prepared by a process comprising the steps of:        -   (a) preparing a mixture of the olefin-maleic anhydride            copolymer, maleic anhydride monomer, an elastomer, and a            peroxide catalyst; and        -   (b) forming the impact modifier in the presence of the            olefin-maleic anhydride copolymer.    -   The polyamide composition any one of the preceding clauses        wherein the polyamide composition has at least one improved        mechanical property compared to a second polyamide composition        that includes the impact modifier and does not include the        olefin-maleic anhydride copolymer.    -   The polyamide composition of any one of the preceding clauses        wherein the polyamide composition has mechanical properties that        match the mechanical properties of a second polyamide        composition that includes the impact modifier and does not        include the olefin-maleic anhydride copolymer, wherein the level        of the impact modifier in the polyamide composition is lower        than the level of the impact modifier in the second polyamide        composition.    -   The polyamide composition of any one of the preceding clauses        wherein the improved mechanical property is impact strength.    -   The polyamide composition of any one of the preceding clauses        wherein the composition has at least one additional improved        mechanical property selected from flex modulus, elongation at        break, and tensile strength, compared to the polyamide.    -   The polyamide composition of any one of the preceding clauses        wherein the polyamide is selected from the group consisting of        nylon-6, nylon 6-6, a copolymer of nylon-6 and nylon 6-6,        nylon-9, nylon-10, nylon-11, nylon-12, nylon 6-10, aromatic        polyamides, elastomeric polyamides, and mixtures thereof.    -   The polyamide composition of any one of the preceding clauses        wherein the polyamide is selected from the group consisting of        nylon-6, nylon 6-6, a copolymer of nylon-6 and nylon 6-6, and        mixtures thereof.    -   The polyamide composition of any one of the preceding clauses        wherein the polyamide is recycled polyamide.    -   The polyamide composition of any one of the preceding clauses        wherein the olefin is selected from ethylene, propylene,        isobutylene, 1-butene, 1-octene, butadiene, styrene, isoprene,        1-hexene, 1-dodecene, dodecene-1, and 1-tetradecene.    -   The polyamide composition of any one of the preceding clauses        wherein the olefin is ethylene.    -   The polyamide composition of any one of the preceding clauses        wherein the olefin-maleic anhydride copolymer is a 1:1        alternating olefin-maleic anhydride copolymer.    -   The polyamide composition of any one of the preceding clauses        wherein the olefin-maleic anhydride copolymer has a weight        average molecular weight of in the range of about 1000 to about        900,000.    -   The polyamide composition of any one of the preceding clauses        wherein the olefin-maleic anhydride copolymer has a weight        average molecular weight of about 60,000    -   The polyamide composition of any one of the preceding clauses        wherein the copolymer has a weight average molecular weight of        about 400,000.    -   The polyamide composition of any one of the preceding clauses        further comprising one or more stabilizing agents    -   The polyamide composition of any one of the preceding clauses        wherein each of the one or more stabilizing agents is        independently selected from a group consisting of cuprous        iodide, potassium iodide, tris        (2,4-di-tert-butylphenyl)phosphite, and        N,N′-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)).    -   The polyamide composition of any one of the preceding clauses        wherein each of the one or more stabilizing agents independently        has a concentration of about 0.01 to about 1.0% w/w.    -   The polyamide composition of any one of the preceding clauses        further comprises a compatibilizer.    -   The polyamide composition of any one of the preceding clauses        wherein the elastomer is a maleic anhydride grafted elastomer.    -   The polyamide composition of any one of the preceding clauses        wherein the impact modifier is selected from a grafted-maleic        anhydride elastomer or a grafted-maleic anhydride terpolymer        where the level of maleic anhydride is from about 0.5% to about        5%.    -   The polyamide composition of any one of the preceding clauses        wherein the level of maleic anhydride is from about 0.8% to        about 2%.    -   The polyamide composition of any one of the preceding clauses        wherein the maleic-anhydride grafted elastomer is selected from        the group consisting of a thermoplastic olefin (TPO), a rubber        copolymer produced in a reactor from ethylene and propylene        (EPR), a rubber terpolymer of ethylene, propylene and        diene-modifier (EPDM), and a plastomer of ethylene with an        alpha-olefin, each of which is grafted with maleic anhydride.    -   The polyamide composition of any one of the preceding clauses        wherein the maleic-anhydride grafted elastomer is a random        terpolymer of ethylene, an acrylic ester and maleic anhydride,        where the level of maleic anhydride is from about 1% to about        5%.    -   The polyamide composition of any one of the preceding clauses        wherein the EPDM, is dicyclopentadiene (DCPD), ethylidene        norbornene (ENB), or vinyl norbornene (VNB), where the level of        the EPDM is from about 1% to about 12%.    -   The polyamide composition of any one of the preceding clauses        wherein the impact modifier is an ethylene-acrylate ester-maleic        anhydride terpolymer.    -   The polyamide composition of any one of the preceding clauses        wherein the acrylate ester is a methyl, propyl, or butyl        acrylate esters.    -   The polyamide composition of any one of the preceding clauses        further comprising one or more additives selected from a UV        stabilizer, a halogenated or non-halogenated flame retardant        additive, a reinforcement material, a heat stabilizer, a light        stabilizer, a polymerization regulator, a plasticizer, a        lubricant, a rheology modifier, a friction modifier, an        anti-blocking agent, an antioxidant, an antistatic agent, a UV        absorber, a pigment, and a dye.    -   The polyamide composition of any one of the preceding clauses        wherein the reinforcement is a mineral, or a fiber, a fabric, a        roving filament, a tube or a yarn, made from glass, carbon,        graphite, cellulose, an aromatic high melting polymer.    -   An article made from the polyamide composition of any one of the        preceding clauses.

METHODS AND EXAMPLES

Materials

Polyamide 6 (grade PA6 NG320HSL) which is recycled quality was obtainedfrom Jamplast Inc. and was used as received. The other Polyamide-6 usedwere prime (also called virgin Nylon-6) grade from BASF called Ultramid®B3S and Ultramid® B24 NO2. Polyamide-6,6 used was a prime (also calledvirgin Nylon-66) grade from BASF called Ultramid® A3K. Care was taken toensure that all grades stayed dry.

A 1:1 ethylene-maleic anhydride alternating copolymer grade ZeMac® E-60(E-60) from Vertellus Specialties Inc. with a weight average molecularweight (MWw) of 60,000 was used in illustrative examples. A 1:1ethylene-maleic anhydride alternating copolymer grade ZeMac® E-400(E-400) from Vertellus Specialties Inc. with a weight average molecularweight (MWw) of 400,000 was also used in other illustrative examples.

Fusabond® N493 (Ethylene-Octene-g-MAh) from DuPont, Royaltuf® 485(EPDM-g-MAh) from Addivant and Amplify GR216 (a plastomer grafted withmaleic anhydride) from The Dow Chemical Co. were used as commerciallyavailable impact modifiers.

Royalene® IM7200 pellets from Lion Copolymer, Optema™ grade TC 141, anethylene-methyl acrylate copolymer resin from ExxonMobil Chemicals witha melt index of 110 g/min and Lotryl® grade 28BA175 an ethylene-butylacrylate copolymer were used as representatives of the elastomerswithout maleic anhydride grafting.

Amplify® GR205 (high density polyethylene grafted with maleic anhydride)from The Dow Chemical Co. was used as a representative non-elastomericgraft copolymer, used as a compatibilizer.

Optema® grade TC 141, ethylene-methyl acrylate copolymer resin fromExxonMobil Chemicals with a melt index of 110 g/min and Amplify® GR216(a plastomer grafted with maleic anhydride) from The Dow Chemical Co.were used as carrier resins for the master batch formulations.

Glass Fiber grade used was ECS 03 T275H from NEG and fed downstream intothe melt with a side feeder during compounding.

Testing

The following TABLE 1 shows the test methods used and the correspondingASTM methods.

TABLE 1 Tests ASTM Method & Conditions Tensile Strength, & Elongation D638 at room temperature (23° C.) Flexural Modulus & Strength D 790 atroom temperature (23° C.) Notched Izod Impact Strength D 256 at roomtemperature (23° C. & −30° C.) Notched Charpy Impact Strength ISO179-2/2 at room temperature (23° C. & −30° C.) Heat DeflectionTemperature ASTM D648 at room temperature (HDT) (23° C.)Compounding with Elastomeric Polymer, Olefin-Maleic Anhydride andPolyamide

Compounding was carried out using a counter-rotating inter-meshing twinscrew extruder (Berstorff 25 mm.) with the temperature profile of 220,235, 255, 245, 240, 240, 240, and 260° C. cooled in a water bath andpelletized. A two-feeder system was used to feed the hopper for thecompounding. The additives (e.g. stabilizer such as anti-oxidant andheat stabilizers) were pre-mixed with olefin-maleic anhydride copolymersand fed through one feeder while carrier resin and other pelletsdescribed herein was fed through the other. The resulting pellets weredried for 12 hours at 70° C. to remove retained moisture. Theformulations are shown in the TABLE 2. The virgin nylon-6 used wasUltramid® B3S and the EPDM pellets used were Royalene® IM 7200 bothdescribed herein. The high density polyethylene grafted maleic anhydrideused showing the optional use of a compatibilizer was Amplify® GR 205(POE-g-MAh). The stabilizers used and the ethylene-maleic anhydridealternating copolymers used are also described herein.

TABLE 2 Stabilizer Package Hindered Virgin EPDM POE-g- Phosphite PhenolExample # Nylon-6 Pellets E-60 E-400 MAh CuI KI Stabilizer AO 1(control) 74% 25% — — — 0.01% 0.09% 0.4% 0.5% 2 72% 25% 2.0% — — 0.01%0.09% 0.4% 0.5% 3 72% 25% — 2.0% — 0.01% 0.09% 0.4% 0.5% 4 72% 25% — —2.0% 0.01% 0.09% 0.4% 0.5%

TABLE 3 ASTM D256 Izod Izod ISO 179-2/2 ASTM D638 ASTM D 790 ImpactImpact Charpy Charpy Tensile Flexural Strength Strength Impact ImpactStrenth Tensile Tensile Flexural Strength @ @ 23° C. @ −30° C. StrengthStrength @ Yield Elongation Modulus Modulus Break (ft- (ft- @ 23° C.@−30° C. Example # (MPa) (%) (MPa) (MPa) (MPa) lb/in) lb/in) (KJ/m²)(KJ/m²) 1 37.77 8.57 1492.6 1402.8 29.96 0.82 0.55 6.47 6.31 (control)(CB) (CB) (CB) (CB) 2 45.96 7.27 1703 1913.3 63.77 1.21 0.74 7.16 5.60(CB) (HB) (CB) (CB) 3 46.58 10.18 1701.8 1871.5 62.74 1.24 0.73 9.549.53 (CB) (HB) (CB) (CB) 4 37.6 29.25 1404.2 1498.8 50.08 2.93 1.8030.70  31.1  (CB) (CB) (NB) (NB) CB indicates complete break, HBindicates some of the specimen broke while the others did not and NBindicates no break for the impact strength values.

After compounding and testing, the results obtained are shown in TABLE3. The data for Example 2, 3 and 4 show improvements in most propertiescompared to Example 1 (control). Overall impact strength is improved;the improvement is higher for the composition with the compatibilizer,Example 4, and less for the non-compatibilized compositions in Example 2and 3. Tensile strength for the composition in Example 3 is higher andmuch more so for that in Example 4. Similarly the flexural strength atbreak is also higher for the compositions in Examples 2 and 3. Theunexpected result is that other properties such as tensile strength andflexural modulus which typically decrease actually improve in spite ofthe 25% of elastomeric component in the compositions of this invention.The processes and compositions described herein can be extended to usingother elastomeric systems such as plastomers and combination ofelastomers to boost the mechanical properties in presence ofethylene-maleic anhydride alternating copolymer of the currentinvention.

Additional compounding examples described in TABLES 4 and 6 were carriedout using a counter-rotating inter-meshing twin screw extruder (CoperionZSK-40) with virgin Polyamide-6 using the temperature settings of 230,240, 240, 240, 240, 250, 250, 250, 250, 250, 245, 240° C. and virginPolyamide-6,6 with NEG's glass fiber fed through side feeder (Grade ECS03 T275H) using temperature settings of 243, 254, 262, 268, 274, 281,280, 276, 271, 274° C. In both these experiments commercially availablegrafted maleic anhydride copolymers Fusabond® N493 (PE-g-MAh) andRoyaltuf® 485 (EPDM-g-MAh) were used.

TABLE 4 Virgin Example # Nylon-6 E-60 PE-g-MAh EPDM-g-MAh  9 (control) 85.0% — 15% — 10 84.36% 0.64% 15% — 11 (control)  85.0% — 15% 12 84.36%0.64% — 15%

TABLE 5 shows test results for the materials obtained after compoundingand injection molding the compositions shown in TABLE 4. Example 9 and11 are controls whose mechanical properties at both room temperature andlow temperature at −30° C. are compared to the properties obtained fromExamples 10 and 12 containing E-60. Both Examples 10 and 12 show markedimprovement in room temperature impact resistance, in addition toimprovements in low temperature impact resistance, tensile strength,elongation and flexural modulus.

TABLE 5 ASTM D638 ASTM D256 Tensile Izod Impact Tensile Elongation ASTMD790 Strength @ Izod Impact Stress @ @ Break Flexural 23° C. (ft-Strength @ Example # Yield (MPa) (%) Modulus (MPa) lb/in) −30° C.(ft-lb/in)  9 (control) 54.5 9.7 1923.6 9.51 3.05 10 58.9 25.7 1950.912.6 3.21 11 (control) 56.7 13.9 2053.6 12.8 2.49 12 56.8 28.4 2058.916.6 2.95

TABLE 6 shows the composition of nylon 6-6 containing 30% glass fibersalong with commercial available grafted maleic anhydride copolymersFusabond® N493 (PE-g-MAh) and Royaltuf® 485 (EPDM-g-MAh) also known asimpact modifier along with olefin-maleic anhydride copolymer (E-60).

TABLE 6 Virgin Glass Example # Nylon-6,6 Fibers E-60 PE-g-MAh EPDM-g-MAh13 (control) 62.5% 30% — 7.5% — 14 62.0% 30% 0.5% 7.5% — 15 (control)62.5% 30% — — 7.5% 16 62.0% 30% 0.5% — 7.5%

The Examples 14 and 16 containing E-60 in TABLE 7 are compared to theirrespective controls without E-60 (Example 13 and 15). It is believedthat E-60 is acting as an interfacial agent between nylon, glass fiberand impact modifiers to yield improvements in all the mechanicalproperties including low temperature impact resistance.

TABLE 7 ASTM D256 ASTM D638 Izod Impact Izod Impact Tensile StressTensile ASTM D790 Strength @ Strength @ @ Yield Elongation @ Flexural23° C. −30° C. Example # (MPa) Break (%) Modulus (MPa) (ft-lb/in)(ft-lb/in) 13 146.0 5.13 6808.9 2.91 2.02 (control) 14 149.7 5.33 6667.33.36 2.09 15 149.8 4.99 6768.3 2.93 2.06 (control) 16 149.8 5.09 7262.93.15 2.34Preparation of Compositions with Recycled and Virgin Polyamide Using theMaster Batch Approach

Also described herein are compositions prepared using a master batchapproach, which typically consists of two steps. In Step 1, the masterbatch is prepared by combining the olefin-maleic anhydride copolymerwith an elastomeric material and in Step 2, the master batch is then“let down” or further compounded into a polyamide. In either of step 1or 2, additional components may be included in the compositions.

Step 1—General Compounded Master Batch Preparation

In addition to the above, compositions of this invention were preparedusing the master batch approach. TABLE 8 shows the composition of eachmasterbatch (MB) MB-1, MB-2 and MB-3; processing was carried out using acounter-rotating inter-meshing twin screw extruder (Berstorff 25 mm.)with the temperature profile of 140, 150, 155, 155, 155, 155, 155, 170°C. resulting into strands that were cooled in a water bath andpelletized. TABLE 8 also shows composition masterbatch MB-4, compoundingof which was carried out in two step process using a counter-rotatinginter-meshing twin screw extruder (Berstorff 52 mm.). In each step theratio of ZeMac® E-60 powder to the amine end-capped Nylon-6 (Ultramid®B24 NO2) was varied to get consistent feeding and avoid any severereaction with amine end-capped Nylon-6. In both steps, the sametemperature profile was used 150, 200, 230, 230, 200, 200, 200, 200,200, 230° C. and the strands were cooled in a water bath and pelletized.A two-feeder system was used to feed the hopper for the compounding. Theadditives (e.g. stabilizer, anti-oxidant, optionally lubricant powders)are pre-mixed with olefin-maleic anhydride copolymers and fed throughone feeder while carrier resin and other pellets described herein wasfed through the other. The resulting pellets were dried for 12 hours at70° C. to remove retained moisture. The formulations used for producingmaster batches with olefin-maleic anhydride copolymers are shown inTABLE 8.

TABLE 8 Materials MB-1 MB-2 MB-3 MB-4 Optema TC141 25.0 25.0 — — Lotryl28BA175 — — 45.0 — Ultramid ® B24 N02 — — — 75.0 Amplify ® GR216 — 50 —— ZeMac ® E60 25.0 10.0 25.0 25.0 Cuprous iodide (CuI) 0.20 0.20 0.20 —Potassium iodide (KI) 1.80 1.80 1.80 — BNX ® 1098¹ 2.00 2.00 2.00 —Benefos ® 1680² 6.00 6.00 6.00 — Acrawax ® C³ 5.00 5.00 20.0 —Polybond ® 3200 12.50 — — — DOW ® LLDPE DNDB-1077 NT 7 22.50 — — — *MB =Master batch Materials¹N,N′-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)]²Tris(2,4-di-tert-butylphenyl)phosphite ³N,N′ Ethylene bis-stearamideStep 2A—Compounding Formulation of Master Batch and Elastomer withRecycled Polyamide-6

The master batch MB-1 and MB-2 formulations shown in TABLE 8 werefurther compounded in second step in a counter-rotating inter-meshingtwin screw extruder (Coperion ZSK-40) with recycled Polyamide-6 usingthe temperature settings of 230, 240, 240, 240, 240, 250, 250, 250, 250,250, 245, 240° C. Both sets of formulations are shown in TABLE 9.

TABLE 9 Recycled Examples Nylon-6 MB1 MB2 PE-g-MAh 17 (control) 100.0% —— — 18 (control) 90.00% — — 10% 19 90.00% 2.50% — 7.5% 20 95.00% — 5.00%— 21 93.75% — 6.25% —

Tensile, flexural and Izod impact strength were measured using themethods listed in TABLE 1. The mechanical tests were carried out afterdrying the compounded pellets for 12 hours at 70° C. to remove retainedmoisture; the samples were used as molded after conditioning the testspecimen as described in the ASTM protocol. Water absorption tests werecarried after drying to equilibration to ensure that all the absorbedwater is between 0.01%-0.3% dryness levels.

TABLE 10 shows the tensile, flexural and notched Izod impact strength atroom temperature for compounded recycled Polyamide-6. In general, theelastomers are known to enhance impact strength but decrease stiffness.

TABLE 10 ASTM D638 ASTM D256 Tensile ASTM D790 Izod Impact Stress @Tensile Flexural Strength Yield Elongation @ Modulus @ 23° C. Example #(MPa) Break (%) (MPa) (ft-lb/in) 17 (control) 63.60 17.21 2640.0 1.30 18(control) 55.62 12.60 1966.7 7.73 19 58.70 61.59 2300.8 14.5 20 64.0340.62 2366.8 2.87 21 62.23 45.83 2376.3 4.30

The results shown in TABLE 10 for Example 18 (control), recycledPolyamide-6, compounded with the maleic anhydride-grafted elastomer(Fusabond® N493), shows improved Izod impact strength compared to thecomposition of control sample shown in Example 17 (control). However,both tensile and flex properties are lower. Even the tensile elongationis lower. Combining the master batch prepared with an elastomer as thecarrier resin, such as that in Example 19, results in high impactstrength and improved tensile strength, elongation and flexural modulus.Surprisingly, a small amount of master batch, 2.5 weight %, incombination with the elastomer at 7.5 weight % (Example 11) not onlyproduces double the impact strength when compared to using tougheneralone at the same overall weight % (Example 19) but produces impactstrength comparable to that obtained from a composition containing agood commercial impact modifier at 20-25 weight %.

The results obtained with the formulations in Examples 20 and 21demonstrate that Izod impact strength is more than double when comparedwith the Examples 17 (control). Although the impact strength is not ashigh as when the elastomer is used alone or in combination with themaster batch nevertheless overall there is an improvement in tensilestrength and impact strength which is still very desirable for manyapplications.

Step 2B—Compounding Formulation of Master Batch and Elastomer withVirgin Polyamide-6 and Polyamide-6,6

The compounded master batch MB-2 and MB-3 shown in TABLE 8 werere-compounded in second step in a counter-rotating inter-meshing twinscrew extruder (Coperion ZSK-40) with virgin Polyamide-6 using thetemperature settings of 230, 240, 240, 240, 240, 250, 250, 250, 250,250, 245, 240° C. The formulations are shown in TABLE 11.

TABLE 11 Virgin Example # Nylon-6 MB-2 MB-3 PE-g-MAh EPDM-g-MAh 22 85.0%— — 15.00% — (control) 23 87.5% 6.25% —  6.25% — 24 85.0% — 2.50% 12.50%— 25 87.0% — 2.50% 10.50% — 26 75.0% — — 25.00% — (control) 27 77.4%5.60% — 17.00% — 28 85.0% — — — 15.00% (control) 29 87.5% 6.25% — — 6.25% 30 85.0% 2.50% — 12.50% 31 87.0% — 2.50% — 10.50% 32 75.0% — — —25.00% (control) 33 77.4% 5.60% — — 17.00%

TABLE 12 shows the mechanical properties of control samples (Examples22, 26, 28 and 32) containing two different commercial impact modifiersused at 15% and 25% levels in virgin Polyamide-6. As a result ofmasterbatch addition in Examples 23-25, 27, 29-31 and 32 shows moderateincrease or retained impact resistance with significant increase intensile strength, elongation and flexural modulus compared to theirrespective control samples. The resulting Polyamide-6 would beconsidered to be superior to commonly known super-tough nylon-6.

TABLE 12 ASTM D638 Tensile ASTM D790 ASTM D256 Stress Tensile FlexuralIzod Impact @ Yield Elongation @ Modulus Strength @ Example # (MPa)Break (%) (MPa) 23° C. (ft-lb/in) 22 (control) 51.3 10.2 1837.1 13.3 2355.5 32.8 2008.1 14.2 24 56.3 43.9 2191.9 14.3 25 56.1 21.7 2011.6 13.226 (control) 39.1 18.1 1468.3 13.4 27 49.0 69.9 1905.1 17.7 28 (control)49.6 23.5 1870.6 14.4 29 60.9 21.5 2415.7 14.8 30 53.0 66.7 1942.7 16.131 61.9 49.9 2384.4 15.3 32 (control) 38.3 35.6 1570.9 18.4 33 46.8 67.71909.3 19.3

TABLE 13 shows the composition of virgin Polyamide-6,6 compounded withimpact modifier and masterbatches using similar equipment as virginPolyamide-6, however a different temperature profile of 243, 254, 262,268, 274, 281, 280, 276, 271, 274° C. was used.

TABLE 13 Virgin PE-g- EPDM- Example # Nylon-6,6 MB-2 MB-3 MB-4 MAh g-MAh34 85.0% — — — 15.0% — (control) 35 87.5% 6.00%  6.5% — 36 85.0% — 2.40%— 12.5% — 37 85.0% — — 2.40% 12.5% — 38 85.0% — — — — 15.0% (control) 3987.5% 6.00% — — —  6.5% 40 85.1% — 2.40% — — 12.5% 41 87.1% — 2.40% — —10.5% 42 75.0% — — — — 25.0% (control) 43 75.0% — 2.00% — — 23.0%

TABLE 14 shows the mechanical properties of compounded compositions ofTABLE 13. The virgin Polyamide-6,6 in the presence of masterbatch ofolefin-maleic anhydride copolymer shows very similar trend of impactresistance improvement and other mechanical property enhancements asobtained in virgin Polyamide-6 (TABLE 12). Only exception is Example 35,where the impact resistance slightly goes down compared to its control(Example 34); however other mechanical properties are significantlyimproved. In other examples, compared to controls samples (Example 34 &38), Examples 36 and 40 shows highly pronounced impact resistanceenhancements in the presence of MB-3 when used in combination of eithertype of impact modifiers (Fusabond and Royaltuf).

TABLE 14 ASTM ASTM D638 D790 ASTM D256 Tensile Tensile Flexural IzodImpact Stress @ Elongation Modulus Strength @ Example # Yield (MPa) @Break (%) (MPa) 23° C. (ft-lb/in) 34 (control) 53.0 19.1 1945.2 11.3 3562.2 27.5 2186.8 11.4 36 58.9 28.2 2145.3 14.8 37 60.3 23.7 2147.5 12.638 (control) 53.2 29.2 2069.0 12.5 39 64.7 26.1 2278.3 11.0 40 58.7 31.02111.1 15.6 41 61.7 27.9 2188.8 12.5 42 (control) 39.4 53.2 1469.0 19.143 44.9 42.2 1583.4 19.4

As can be seen for control Examples 44, 49 and 52, shown in TABLE 15,the presence of an elastomer or an impact modifier generally results ina lower heat deflection/heat distortion temperature (HDT). The processesand compositions described herein surprisingly enhance the HDT even ofvirgin Nylonsthat are compounded with an elastomer or an impactmodifier. TABLE 15 shows the composition and effect of ZeMac® E-60 andits masterbatches on HDT of virgin Nylon-6 and Nylon-66 in the presenceof elastomer or an impact modifier.

TABLE 15 ASTM Virgin D648 Virgin Nylon- PE-g- EPDM- HDT @ Example #Nylon-6 6,6 MAh g-MAh E-60 MB-2 MB-3 MB-4 66 psi (° C.) 44 (control)85.00% — 15.0% — — — — — 148.8 45 86.87% — 12.5% — 0.625% — — — 157.8 4687.50% — 6.25% — — 6.25% — — 153.3 47 85.10% — 12.5% — — — — 2.4% 153.348 87.10% — 10.5% — — — — 2.4% 155.3 49 (control) 85.00% — — 15.0% — — —— 145.9 50 86.87% — — 12.5% 0.625% — — — 161.9 51 87.10% — — 10.5% — — —2.4% 157.7 52 (control) — 85.00% 15.0% — — — — — 187.6 53 — 86.90% 12.5%— 0.60% — — — 203.4 54 — 87.25% 6.25% — — 6.50% — — 214.0 55 — 85.10%12.5% — — — 2.4% — 213.7 56 — 85.10% 12.5% — — — — 2.4% 206.9

Examples 45-48, 50-51 and 53-56 in TABLE 15 show enhanced HDT valueswhen compared to their respective control samples. Some of thecompositions shown in TABLE 15 are similar to those shown in TABLES 11and 13 except examples 45, 48, 50, 51, 53 and 56. The Examples in TABLE15 which are similar to TABLES 11 and 13 containing masterbatches andimpact modifiers not only show higher values of impact resistance butalso show enhanced mechanical and thermal properties.

Preparation of Articles with Composition

The compositions of the present invention herein may be formed intoarticles using methods known to those skilled in the art. Illustrativeexamples include injection molding, blow molding, extrusion, and thelike. The Polyamide-6 compositions of TABLE 11 were injection moldedinto various shapes such as dog bone and plaque. The molding was carriedout using the following equipment and process conditions:

-   -   i. Vandorn Intelect 110T injection molding press equipped with a        standard single screw having diameter of 35 mm, an L/D ratio        equal 20/1;    -   ii. a barrel temperature between 225-250° C. with increasing        profile;    -   iii. a nozzle temperature of 238° C.;    -   iv. a mold temperature of 83° C.;    -   v. a mold for ASTM D638 Type I for tensile bars;    -   vi. a mold with plaque dimension of 4.25 in×4.25 in×0.125 in;    -   vii. a screw rotation speed of 100 RPM;    -   viii. injection at speed 1-1.5 in/sec;    -   ix. a specific injection pressure of 2300 psi and hold pressure        of 800 psi;    -   x. a hold time of 8-10 sec.

While several illustrative embodiments of methods for production ofpolyamide compositions with high values of impact resistance, mechanicalproperties, thermal properties and methods for use of the compositionsinto articles have been described herein, the embodiments are merelyoffered by way of non-limiting examples of the invention describedherein. Many variations and modifications of the embodiments describedherein will be apparent in light of the disclosure. It is therefore tobe understood that changes and modifications may be made by one of skillin the art, and equivalents may be substituted for elements thereof,without departing from the scope of the invention.

Further, in describing representative embodiments, the disclosure mayhave presented a method and/or process as a particular sequence ofsteps. However, to the extent that the method or process does not relyon the particular order of steps set forth herein, the method or processshould not be limited to the particular sequence of steps described. Itwill be appreciated that other sequences of steps may be possible.Therefore, the particular order of the steps disclosed herein should notbe construed as limitations on the claims. In addition, the claimsdirected to a method and/or process should not be limited to theperformance of their steps in the order written, and it will be readilyappreciated that the sequences may be varied and still remain within thespirit and scope of the present invention.

What is claimed is:
 1. A polyamide composition produced by a processcomprising the step of compounding a mixture comprising a polyamide, a1:1 alternating olefin-maleic anhydride copolymer, wherein the olefin isselected from the group consisting of ethylene, propylene, isobutylene,1-butene, 1-octene, butadiene, isoprene, 1-hexene, 1-dodecene,dodecene-1, and 1-tetradecene, and an impact modifier selected from thegroup consisting of a grafted-maleic anhydride elastomer and agrafted-maleic anhydride terpolymer.
 2. The polyamide composition ofclaim 1, wherein the polyamide is selected from the group consisting ofnylon-6, nylon 6-6, a copolymer of nylon-6and nylon 6-6, nylon-9,nylon-10, nylon-11, nylon-12, nylon 6-10, aromatic polyamides,elastomeric polyamides, and mixtures thereof.
 3. The polyamidecomposition of claim 1, wherein the polyamide is selected from the groupconsisting of nylon-6, nylon 6-6, a copolymer of nylon-6and nylon 6 6,and mixtures thereof.
 4. The polyamide composition of claim 1, whereinthe polyamide is recycled polyamide.
 5. The polyamide composition ofclaim 1, wherein the olefin is ethylene.
 6. The polyamide composition ofclaim 1, wherein the olefin-maleic anhydride copolymer has a weightaverage molecular weight of about 1000 to about 900,000.
 7. Thepolyamide composition of claim 1, wherein the olefin-maleic anhydridecopolymer has a weight average molecular weight of about 60,000 to about400,000.
 8. The polyamide composition of claim 1, further comprising oneor more stabilizing agents.
 9. The polyamide composition of claim 8,wherein each of the one or more stabilizing agents is independentlyselected from the group consisting of cuprous iodide, potassium iodide,tris-(2,4-di-tert-butylphenyl)phosphite, andN,N′-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)).10. The polyamide composition of claim 8, wherein each of the one ormore stabilizing agents independently has a concentration of about 0.01to about 1.0% w/w of the polyamide composition.
 11. The polyamidecomposition of claim 1, further comprising a compatibilizer selectedfrom the group consisting of acrylic acid modified polypropylenehomopolymer, maleic anhydride modified polypropylene homopolymer,ethylene acrylic acid copolymer, and ethylene-octene copolymer graftedwith maleic anhydride.
 12. The polyamide composition of claim 1, whereinthe impact modifier is a grafted-maleic anhydride elastomer or agrafted-maleic anhydride terpolymer having a maleic anhydride content offrom about 0.5% to about 5%.
 13. The polyamide composition of claim 12,wherein the impact modifier is a grafted-maleic anhydride elastomer orterpolymer having a maleic anhydride content in the range of 0.8 to 2%.14. The polyamide composition of claim 1, further comprising one or moreadditives selected from the group consisting of a UV stabilizer, ahalogenated or non-halogenated flame retardant additive, a reinforcementmaterial, a heat stabilizer, a light stabilizer, a polymerizationregulator, a plasticizer, a lubricant, a rheology modifier, a frictionmodifier, an anti-blocking agent, an antioxidant, an antistatic agent, aUV absorber, a pigment, and a dye.
 15. The polyamide composition ofclaim 14, wherein the reinforcement is a mineral, a glass fiber, a glassfabric, a glass roving filament, a glass tube, a glass yarn, carbon,graphite, or cellulose.
 16. The polyamide composition of claim 1,wherein the impact modifier is selected from the group consisting of arubber copolymer produced in a reactor from ethylene and propylene (EPR)grafted with maleic anhydride, a rubber terpolymer of ethylene,propylene and diene-modifier (EPDM) grafted with maleic anhydride, andan ethylene alpha-olefin copolymer grafted with maleic anhydride.
 17. Anarticle comprising a polyamide composition according to claim
 1. 18. Apolyamide composition produced by a process comprising the steps of: (a)preparing a master batch composition comprising an impact modifierselected from the group consisting of a grafted-maleic anhydrideelastomer and a grafted-maleic anhydride terpolymer and a 1:1alternating olefin-maleic anhydride copolymer, wherein the olefin isselected from the group consisting of ethylene, propylene, isobutylene,1-butene, 1-octene, butadiene, isoprene, 1-hexene, 1-dodecene,dodecene-1, and 1-tetradecene; and (b) compounding a polyamide with themaster batch composition.
 19. The polyamide composition of claim 18,wherein the impact modifier is a grafted-maleic anhydride elastomer or agrafted-maleic anhydride terpolymer having a maleic anhydride content offrom about 0.5% to about 5%.
 20. The polyamide composition of claim 18,wherein the impact modifier is a grafted-maleic anhydride elastomer orterpolymer having a maleic anhydride content in the range of 0.8 to 2%.21. The polyamide composition of claim 18, wherein the impact modifieris selected from the group consisting of a rubber copolymer produced ina reactor from ethylene and propylene (EPR) grafted with maleicanhydride, a rubber terpolymer of ethylene, propylene and diene-modifier(EPDM) grafted with maleic anhydride, and an ethylene-alpha-olefincopolymer grafted with maleic anhydride.
 22. The polyamide compositionof claim 18, wherein the master batch further comprises one or morestabilizing agents.
 23. The polyamide composition of claim 22, whereinthe one or more stabilizing agents is selected from the group consistingof cuprous iodide, potassium iodide,tris-(2,4-di-tert-butylphenyl)phosphite, and N,N′-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)).
 24. Thepolyamide composition of claim 18, wherein the master batch furthercomprises one or more compatibilizers selected from the group consistingof acrylic acid modified polypropylene homopolymer, maleic anhydridemodified polypropylene homopolymer, ethylene acrylic acid copolymer, andethylene-octene copolymer grafted with maleic anhydride.
 25. Thepolyamide composition of claim 18, wherein the master batch furthercomprises one or more stabilizing agents and one or more compatibilizersselected from the group consisting of acrylic acid modifiedpolypropylene homopolymer, maleic anhydride modified polypropylenehomopolymer, ethylene acrylic acid copolymer, and ethylene-octenecopolymer grafted with maleic anhydride.